While integrated circuits are continually being reduced in size, some elements remain as stumbling blocks in the march toward smaller, lighter devices. Among these are the power supplies; in particular batteries. Batteries commonly constitute the heaviest and in many instances, the most space consuming part of a device. This is particularly so in miniature devices such as small, monolithic sensors.
One approach to addressing this problem is the development of passive devices such as RFID tags, which scavenge their energy from readers by making use of coils that are excited by RF fields emitted by the readers. However, situations present themselves where active devices are required with their own power supplies. WiFi tags, for example, are active sensors that can relay information to an access point without the need for readers to externally provide the power. The present invention seeks to address some of these issues.